tailieunhanh - Báo cáo hóa học: " High Activity of Hexagonal Ag/Pt Nanoshell Catalyst for Oxygen Electroreduction"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: High Activity of Hexagonal Ag/Pt Nanoshell Catalyst for Oxygen Electroreduction | Nanoscale Res Lett 2009 4 193-196 DOI S11671-008-9224-3 NANO EXPRESS High Activity of Hexagonal Ag Pt Nanoshell Catalyst for Oxygen Electroreduction Chien-Liang Lee Chun-Ming Tseng Chen-Chung Wu Tsung-Chia Chou Ciou-Mei Syu Received 1 November 2008 Accepted 20 November 2008 Published online 4 December 2008 to the authors 2008 Abstract Hexagonal Ag Pt nanoshells were prepared by using a hexagonal Ag nanoplate as the displacement template and by introducing Pt ions. The prepared Ag Pt nanoshells played the role of an electrocatalyst in an oxygen reduction process. Compared to spherical Pt and Ag Pt nanoparticles the hexagonal Ag Pt nanoshells showed higher activity for oxygen electroreduction. Keywords Nanoparticles Electrocatalysts In a low-temperature fuel cell polarization often occurs at the oxygen electrode. In order to reduce the effect of polarization on the electrode it is necessary to enhance the activity of the electrocatalysts involved in the oxygen reduction reaction. Frequently spherical Pt nanoparticles are used as the electrocatalysts 1-3 . On the basis of the catalytic model increasing the number of active sites on the surface of an electrocatalyst is an option for improving its electrochemical activity. Recently nonspherical nanoparticles have also been found to be promising catalysts 4-8 . These nanoparticles promote catalytic reactions because higher atomic fractions are located at the corners and edges of the nanoparticles 8 . Additionally hollow metallic nanoparticles have attracted interest in the field of optics 9 and catalysis 4 due to their unique properties. We have recently found that triangular Ag Pd nanocatalysts in an electroless copper bath exhibit high activity 4 . . Lee H . Tseng . Wu . Chou . Syu Department of Chemical and Materials Engineering National Kaohsiung University of Applied Science No. 415 Chien Kung Rd. Kaohsiung 807 Taiwan ROC e-mail cl_lee@ The present study investigates the .